java.util
public class Timer extends Object
The normal scheduling will result in a more or less even delay in time between successive executions, but the executions could drift in time if the task (or other tasks) takes a long time to execute. Fixed delay scheduling guarantees more or less that the task will be executed at a specific time, but if there is ever a delay in execution then the period between successive executions will be shorter. The first method of repeated scheduling is preferred for repeated tasks in response to user interaction, the second method of repeated scheduling is preferred for tasks that act like alarms.
The Timer keeps a binary heap as a task priority queue which means that scheduling and serving of a task in a queue of n tasks costs O(log n).
Since: 1.3
See Also: TimerTask
| Constructor Summary | |
|---|---|
| Timer()
Creates a new Timer with a non daemon Thread as Scheduler, with normal
priority and a default name. | |
| Timer(boolean daemon)
Creates a new Timer with a daemon Thread as scheduler if daemon is true,
with normal priority and a default name. | |
| Timer(String name)
Create a new Timer whose Thread has the indicated name. | |
| Timer(String name, boolean daemon)
Create a new Timer whose Thread has the indicated name. | |
| Method Summary | |
|---|---|
| void | cancel()
Cancels the execution of the scheduler. |
| protected void | finalize()
Tells the scheduler that the Timer task died
so there will be no more new tasks scheduled. |
| int | purge()
Removes all cancelled tasks from the queue. |
| void | schedule(TimerTask task, Date date)
Schedules the task at the specified data for one time execution.
|
| void | schedule(TimerTask task, Date date, long period)
Schedules the task at the specified date and reschedules the task every
period milliseconds after the last execution of the task finishes until
this timer or the task is canceled.
|
| void | schedule(TimerTask task, long delay)
Schedules the task after the specified delay milliseconds for one time
execution.
|
| void | schedule(TimerTask task, long delay, long period)
Schedules the task after the delay milliseconds and reschedules the
task every period milliseconds after the last execution of the task
finishes until this timer or the task is canceled.
|
| void | scheduleAtFixedRate(TimerTask task, Date date, long period)
Schedules the task at the specified date and reschedules the task at a
fixed rate every period milliseconds until this timer or the task is
canceled.
|
| void | scheduleAtFixedRate(TimerTask task, long delay, long period)
Schedules the task after the delay milliseconds and reschedules the task
at a fixed rate every period milliseconds until this timer or the task
is canceled.
|
Parameters: name the name of the Thread
Since: 1.5
Parameters: name the name of the Thread daemon true if the Thread should be a daemon thread
Since: 1.5
Returns: the number of tasks removed
Since: 1.5
Throws: IllegalArgumentException if date.getTime() is negative IllegalStateException if the task was already scheduled or canceled or this Timer is canceled or the scheduler thread has died
Throws: IllegalArgumentException if period or date.getTime() is negative IllegalStateException if the task was already scheduled or canceled or this Timer is canceled or the scheduler thread has died
Throws: IllegalArgumentException if delay or System.currentTimeMillis + delay is negative IllegalStateException if the task was already scheduled or canceled or this Timer is canceled or the scheduler thread has died
Throws: IllegalArgumentException if delay or period is negative IllegalStateException if the task was already scheduled or canceled or this Timer is canceled or the scheduler thread has died
Throws: IllegalArgumentException if period or date.getTime() is negative IllegalStateException if the task was already scheduled or canceled or this Timer is canceled or the scheduler thread has died
Throws: IllegalArgumentException if delay or System.currentTimeMillis + delay is negative IllegalStateException if the task was already scheduled or canceled or this Timer is canceled or the scheduler thread has died